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Discussion Starter · #1 ·
In the hope of curing a oil leakage/burning problem, i want to swap my K24 with a lower mileage unit. Will be a straight replacement for like.

What's the fastest and easiest way of doing this?

My latest thinking is to pull the heat shields, strut brace, and OTE pipe off, then pull back the turbo air inlet pipe, but not remove it. From there, remove the hardlines, wastegate actuator, and compressor housing. I assume the CHRA comes off of the exhaust housing fairly easily? Then just slip the new CHRA in and reassemble?

Or, is it easier to remove the entire turbo without disassembling it.... as in just unbolting it from the header and downpipe?
 

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I don't know if you'll be able to get to all the CHRA-turbine housing bolts with it in there. With the compressor housing off, you can pull the CHRA/turbine housing out with some convincing, it'll be tight.
 

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I would expect to pull the entire turbo. You can do it from above with the head still in place - have done it myself. Unbolt it from the header and dp as you suggested. Also, have you vetted out valve seals as a potential cause of oil loss before attributing it to the turbo?
 

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Discussion Starter · #4 ·
OK, i guess i'll yank the entire turbo as a unit.

This oil leak is the most ridiculous problem ever. Oil is leaking at the upper block vent to flame trap hose connection. As in the large, thick vent on the front of the block that connects to the 90 deg hose the connects with the side of the flame trap.

So far, i've replaced:
Valve stem seals
Dipstick to block seal
Oil pressure sensor and sealing ring
Entire PCV system -- combo hose, flame trap, PCV to intake banjo bolt, flame trap to block connector, upper block vent to flame trap hose, valve cover to flame trap hose.
Turbo air inlet pipe

Engine oil flushed, just in case this is sludge caused
Compression tested @ ~ 135-150 across the cylinders
Leak down tested acceptable.
Definitely have vacuum at the valve cover with no significant vac leaks.
No massive oil pooling in the intercooler - haven't checked lately, but there was none when i upgraded last year, when still had problem
No hugely unusual smoking at the exhaust or leaking when parked

What's left that could cause this??? Only difficult things..... Oil control rings, valve guides...
Lastly, i was thinking that MAYBE the turbo is spitting a little oil into the cat/downpipe and I don't see the smoke. Or, the turbo isn't "drawing" enough vacuum/vent to sufficiently control crank vapors through the air intlet pipe?
 

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Sounds like you are chasing your tail. I wouldn't assume the turbo is bad. You say you have a leak at the block to flame trap - sure it's seated well and nothing is broken or off at that joint? That's a low pressure point on the block so would have to be some serious blowby to push oil out there. I would expect you'd be leaking at other seals and popping the dipstick out if that were the case. What about a cam seal leak that tracks down to that point and appears as it's from the block to flame trap?

Are you actually consuming lots of oil or burning/smoking out the exhaust?
 

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Discussion Starter · #6 ·
No visible smoke out the exhaust. Oil is magically disappearing at about a quart every 600 mi or so. The motor only leaks through the aforementioned flame trap to block hose. I've disassembled and replaced everything nearby in the vicinity and am absolutely sure this is where the leak is. Losing a quart every 600 mi should make a HUGE mess. This is a decent leak, but it's not that crazy to the point where there's oil coating the entire underbody (which is what 1qt per 600 mi should look like)

The block to flame trap connection is definitely PERFECT. Originally, the car came with an OEM hose that was in good shape, yet leaked. I replaced the hose once with a new MTC brand hose, which leaked. I assumed it was a crap hose, which it was, but then switched to an iPd silicone nitrile, which leaks again. Thinking i'm a hack job at this, i had a professional Volvo specialist install the iPd hose, which is perfect. It's a fantastic part with the proper hose clamp.

Honestly not sure what to think. Ideas???

So, that leaves only the:
Turbo -- maybe it's not providing enough venturi effect to pull crank vapors? Or is just blowing/burning oil itself?
Oil control rings
Valve guides
Cracked block at the flange, which is super thick
 
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